Adjustable bandstop filter

Abstract

The embodiment of the invention discloses an adjustable bandstop filter. The filter comprises a metal layer, a substrate, a resonator unit, a low-voltage external electrode and a high-resistance offset line, wherein two first crack lines are used for dividing the metal layer into a signal line and two earth lines located on the two sides of the signal line respectively; the adjustable bandstop filter is symmetrical relative to the transverse central line of the signal line; the resonator unit comprises a plurality of crack rings, a plurality of crack connection lines and a plurality of integrated switching units, which are arranged on the earth line on the same side; the plurality of crack rings are distributed at intervals along the extending direction of the first crack line and are communicated in sequence through the crack connection lines; each integrated switching unit comprises a second crack line and an MEMS (Micro-electromechanical Systems) switch; each MEMS switch comprises a bridge pier, a cantilever beam, a contact body and a high-voltage external electrode; and the plurality of integrated switching units of the resonator unit are arranged at intervals along the extending direction of the first crack lines. With the adoption of the embodiment of the invention, the functions that the central frequency of the bandstop filter can be adjusted and the bandstop filter can be used as a through transmission line can be realized, and the reliability of adjusting the central frequency can be improved.

Description

technical field [0001] The invention relates to the technical field of radio frequency micro-electromechanical systems, in particular to an adjustable band-stop filter. Background technique [0002] Filters are the core components of communication systems. Bandstop filters (BSF for short) refer to filters that can pass most frequency components but attenuate certain ranges of frequency components to extremely low levels. The tunable band-stop filter can replace the functions of multiple non-tunable band-stop filters, greatly reducing the system cost. The coplanar waveguide tunable band-stop filter based on MEMS technology has the advantages of low cost, small size, and easy integration. It is a research hotspot in the field of international communication. [0003] The traditional coplanar waveguide tunable band-stop filter is to change the resonant frequency of the resonator by changing the height of the MEMS switch. This design results in: the adjustment accuracy of the ce...

AI Technical Summary

Problems solved by technology

[0003] The traditional coplanar waveguide tunable band-stop filter is to change the resonant frequency of the resonator by changing the height of the MEMS switch. This design results in: the adjustment accuracy of the center frequency decreases sharply with the increase in the number of uses, and the reliability of the filter works lower

This is mainly because: the adjustment of the height of the MEMS switch is realized through the deformation of the switch beam. After multiple adjustments, the switch beam is prone to fatigue, and the height positioning accuracy of the switch beam drops sharply.

At the same time, the existing tunable filter can only be used as a filter, and cannot be used as a straight-through transmission line, which brings a lot of inconvenience to the use

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